Abstract: Wangu (SI4) point, as the source point of the small intestine meridian of hand-taiyang, has theoretical origins traceable to the Ling Shu·Ben Shu (The Spiritual Pivot) and Nan Jing (The Classic of Difficult Issues). It plays a significant role in connecting the primordial qi of the triple energizer and regulating the functions of the zang-fu organs. This study employs a combination of bibliometric and theoretical analysis to systematically compare the location, indications, needling and moxibustion techniques, and combination patterns of Wangu (SI4) point as recorded in the Zhen Jiu Jia Yi Jing (The Systematic Classic of Acupuncture and Moxibustion) and Zhen Jiu Da Cheng( The Great Compendium of Acupuncture and Moxibustion). The research reveals that while the Zhen Jiu Da Cheng inherits the foundational theories of the Zhen Jiu Jia Yi Jing,it expands the indications of Wangu (SI4) point (from 5 categories to 8 categories, covering over 20 conditions such as jaundice, stroke, and limb pain and numbness), and establishes a systematic clinical application framework including "source-connecting point combination," "layered needling techniques, " and "quantified reinforcing and reducing methods." Moreover, it integrates the point into the theoretical frameworks of midnight-noon ebb-flow and the twelve source points, achieving a transition from symptomatic treatment to syndrome differentiation-based treatment. Modern clinical studies have also validated its efficacy in improving limb function post-stroke and providing analgesia, confirming the scientific value of classical traditional Chinese medicine theories. This study elucidates the evolutionary path of Wangu (SI4) point from theoretical foundation to clinical maturity,providing a paradigm for the modern transformation and precise application of classical acupuncture theory.